Implementing tiles with different states...

Engines, Libraries and Tools Xith3D Forums
#1

Hi!

I have big tiled square (textured like a tiles). And I need to implement following behaviour for tiled surface: I need to be able to make some tiles of my choice to get transparent (dissapear) + I would like to decal holls on some tiles of choice.

One way I tried is - just making tiles as individual shapes - working fine of caurse, but performance wisely - not acceptable…

I wonder can I get desirable effect having only one big polygon shape (instead of individual shapes), and playing somehow with its texturing only?
The problems with individual ones is - that I need many of them, and this affect performance considerably.

Have anybody tried to do something similar? Any advices would be very much appreciated.

Sincerely,
bohdan.

#2

You could try to work with TextureUnitStates. But You have to know, that the number of TextureUnitStates you can use is limited by the grafic-card (mine, for example, only supports two, but it’s already pretty old - most now have 4 to 16)

#3

There is a little bug in Xith ; it allways take for granted that the graphic card has 4 texture units.
On my Geforce2 GTS, I only have 2. This causes the LWJGL renderer to assert (the JOGL renderer silently ignores this error).
I have already filled a bug report for this.

            Vincent
#4

I’m going to look at this

#5

Could you use multitexturing as described in: http://xith.org/tutes/GettingStarted/html/more_fun_with_textures.html?
If you wanna do something like persist zillions of bullet holes, you could divide the surface up and add a texture for each section in clamp mode. You could trace the intersection using a similiar method to mouse picking, or using your own math by ray-plane intersection, then draw a new overlay texture using Graphics2D for the section and swap it out. I’ve never tried this before so I don’t know if it would be fast enough. I don’t know how many textures a single shape can take or how the overlap effect performance, if at all. I don’t know if this idea scales well for huge areas, you might need to make more shapes for a compromise.

#6

Yes you can have just a big Shape3D with a Grid geometry… and then you just play with UV texture coordinates… But that’s a huge job.

#7

Thank you very much for suggestions!

Actually, at the moment I have this implemented just as JViz suggests. To modify the tile texture I am drawing the texture using Graphics2D, for “decals”. But I have individual shapes for tiles.

I can use TexUnitsStates here too (for individual shapes still, I mean), but because of my celtic TNT2 I would be limitted… especially when I need lets say few decals for a tile… I can always easily prepare my texture with Graphics2D, but with states - it would be either difficult to achieve (in my particular case) or even not possible… probably. I may end up then drawing states textures with the Graphics2D :).
And I don’t see big help of Ordered/DecalGroups here for me too…

So basically even to manage one tile - I see, that multytexturing is not helping me much (not to the level I would like to)… And unlikely it will help when switching to single Shape3D geometry for bunch of tiles… i think… hmm…

Anyhow, appreciate your thoughts, guys!

#8

MagicSpark,

Sorry, can you specify what you mean by “big Shape3D with a Grid geometry”? Do you mean that creating big shape (instead of individual tiles) not as a one big square (4 vertices), but as set of many vertices may help?

I can specify one texcoords for one vertex… I don’t see how “Grid geometry” may help (as in case of flat shape)… ???

#9

you can specify texcoordinates for every TextureUnitState for every vertex

#10

That’s what I mean, and Arne is right.
You can have ONE Shape3D with ONE geometry and ONE texture composed of multiple squares corresponding to the different tiles types.

#11

Thanks guys! Appreciate you help!

#12

Did you get it running ?

#13

look at my fun with texture example on xith site. In it I mess with texture coords and multi texturing…

http://xith.org/tutes/GettingStarted/html/more_fun_with_textures.html

#14

“Mess” is actually the right word. Anyway, great work hawkwind it’s more convenient to have a tutorial than to read in the Javadoc. I think a rewrite/split of the texture tutorial would be great.

#15

[quote="<MagicSpark.org [ BlueSky ]>,post:12,topic:26419"]
Did you get it running ?
[/quote]
Well, I believe I understood the approach you sugest, but I really have too many “states” for a tile… For example number of decals I may need - is kind of unlimited, could not be predefined… It seems I need to draw tile texture dynamically anyhow…
I see it difficult to cover by playing with texCoords and or using texture states (actually, originaly when I was posting the question I didn’t realise there is limit for a number of states you can use)…

Yes, have studied it in the first turn :slight_smile: Thanks!

For now I just left it as it was with individual shapes… Anyhow, thanks for sugestions! It was helpfull information for me!

#16

And maybe individual shapes is better for performances, since we have frustum culling in Xith. (This is only if you don’t see your terrain from very far)

#17

I see… Yes, when I’m close to tiles, and there are not many of them visible - performance is great. But sometimes I need to have look from far a way - yes, then there is considerable drop of performance…
But I decide I can live with it for now…

Thanks!